# dialog.pl
# A Perl program that inputs sentences and tries to respond.
# S. Tanimoto, for CSE 341.

use strict;

# Sample data:
my $testSent;
$testSent = "This is a test.";
$testSent = "Go jump in a lake!";

# the most important function:

sub rewrite {
    my $sent = shift;
    my $punc;
    my $mode;
    my $ans;
if ($sent =~ /([\.\?\!])$/) { $punc = $1; }

if ($punc eq ".") { $mode = "declarative"; }
if ($punc eq "?") { $mode = "interrogative"; }
if ($punc eq "!") { $mode = "imperative"; }

# print "This is a $mode sentence: $sent\n";

if ($mode eq "declarative") {
    $sent =~ s/.$/?/;
    $sent =~ s/you/YYOOUU/g;
    $sent =~ s/I|me/you/g;
    $sent =~ s/YYOOUU/me/g;
    $ans = "Are you sure " . lc($sent);
}
elsif
   ($mode eq "interrogative") {
    $ans = "Why do you want to know?";
}
elsif
   ($mode eq "imperative") {
    $sent =~ s/.$/./;
    $ans = "No, YOU should " . lc($sent);
}
else {
    $ans = "I can't understand you when you say, " . lc($sent);
}
    return $ans;
}

my $done = 0;
while (! $done) {
    print "Enter a sentence:\n";
    my $sent = <STDIN>;
    chomp($sent);
    if ($sent eq "") { $done = 1; }
    if (! $done) {my $ans = rewrite($sent);
		 print $ans . "\n"; }
}